On the eve of a federal deadline for states to say whether they will run their own exchanges, a top health care policy official told lawmakers that the exchanges will start enrolling eligible families starting on Oct. 1.

"I am confident that states and the federal government will be ready in 10 months, when consumers in all states can begin to apply," Gary Cohen, director of the Center for Consumer Information and Insurance Oversight, told a House panel. . . .

In written testimony, Cohen said that while 15 states have told the administration they will operate exchanges, 11 others have opted for versions that will require major involvement by the federal government.

Experts say the number of states planning to operate their own exchanges could reach 18, plus the District of Columbia, by the time the deadline arrives Friday. . . .